Prior art of possible relevance includes the following U.S. Pat. Nos.: Cain 3,049,633; Smith 3,743,867; Kullmann 4,037,124; Deis 4,037,312; and Hunt 4,139,789.
It has long been known that the efficiency of rotary electric machines can be increased by cooling the windings thereof. Generally, efforts at cooling have involved either the use of hollow electrical conductors which in turn serve as the conduits for the coolant or confining the windings in a passage and flowing the coolant through such passage such that it contacts the conductors in heat exchange relation.
The former approach, while quite effective, is quite complex mechanically and hydraulically with the result that it is quite expensive and does not lend itself well to small, lightweight application such as generators utilized in aircraft.
The latter approach also works well but as typically implemented, requires the use of mechanical spacers in the windings thereby complicating the construction and/or results in unequally sized fluid flow paths which encourage non-uniform heat transfer and create balance problems during operation of the machine where employed to cool rotor windings, particularly in high speed machines.
The present invention is directed to overcoming one or more of the above problems.